What is a thermal overload relay?

Thermal overload relays are economic electromechanical protection devices for the main circuit. They offer reliable protection for motors in the event of overload or phase failure. The thermal overload relay can make up a compact starting solution together with contactors.

What are 2 types of overload relays?

A few different types of overload relays include Bimetal Overloads, Ambient-Compensated Overload Relay, and Electronic Overload Relays. Bimetal Overloads use a bimetal strip that acts as a trip lever. When there is an overload condition, the bimetal strip becomes heated and will bend to close and trip the circuit.

What is an electronic overload relay?

The electronic overload relay is a microprocessor-controlled device designed to protect three-phase and one-phase motors against excessive temperature rise from overload and phase failure. An electronic overload relay offers reliable and fast protection for motors in the event of overload or phase failure.

Where are thermal overload relays used?

Thermal overload relays are installed in the main circuit when electromechanical protection is adequate. This protects the motor in case of phase failure or overload. The thermal overload relay does not directly shut down the load. Instead, it triggers one or several auxiliary contacts which then disconnect the motor.

What is the purpose of thermal overload protection at the motor?

The Purpose of a Thermal Protector The thermal protection is present to turn the motor off when excessive heat is generated within the motor circuitry. This safety feature halts the temperature climb before it can burn up the motor.

How do thermal overloads operate?

A thermal overload relay works in the principle of electro-thermal properties in a bimetallic strip. When the bimetallic strips heat up, the trip contact is activated that in turn breaks the power supply to the contactor coil, de-energizing it and breaking the current flow to the motor.

What is the greatest difference between thermal type and magnetic type overload relays?

What is the major difference in characteristics between thermal-type and magnetic-type overload relays? Thermal overload relays are sensitive to ambient temperature and magnetic type are not.

How does a thermal relay work?

The basic working principle of thermal relay is that, when a bimetallic strip is heated up by a heating coil carrying over current of the system, it bends and makes normally open contacts.

What is the use of thermal relay?

Thermal relays are protective electrical appliances used for overload protection of motors or other electrical equipment and electrical circuits.